DE3873572T2 - GUIDE FOR A TRACHAL TUBE. - Google Patents

Description

The present invention relates to a guide for assisting medical personnel in inserting an endotracheal tube into the trachea, or windpipe, of a patient.

Endotracheal intubation is the technique of inserting a tube into the trachea of a patient to assist or facilitate breathing. It is commonly used in surgery and in emergency situations, e.g. in the case of injury victims or those in cardiac arrest who are experiencing respiratory distress. Several other techniques are known to secure an airway, such as the esophageal obturator airway, the esophageal gastric tube airway, and the pharyngeal tracheal lumen airway, as well as mouth-to-mouth or bag-to-mask ventilation. However, none of these techniques create an airway into the trachea and thus none of them can truly secure the airway to prevent possible aspiration of blood, vomit or other foreign material into the lungs. Furthermore, some of these techniques can cause additional injury to the patient.

Consequently, tracheal intubation is generally considered to be the better method of securing an airway and ensuring adequate air supply. However, this technique has the disadvantage of requiring significant skill and experience on the part of the operator. Clumsy insertion can cause additional injuries, e.g. to the front incisors. Another problem is that many existing techniques for inserting a tube into the trachea require a special position of the patient's head and thus cannot be used on trauma victims because of the possibility of additional spinal cord injuries until cervical spine fractures can be ruled out.

A laryngoscope is usually used to assist in the placement of the endotracheal tube. This allows the operator to observe the insertion of the tube, but requires that the patient be placed in a head-back position, which is not usually possible in trauma victims. The larynx cannot then be visualized if the pharyngeal cavity is filled with blood or vomit. Laryngoscopes are relatively difficult instruments to handle even for trained medical personnel. Thus, they are not usually suitable for use by field medical support personnel.

Other endotracheal intubation techniques involve inserting the tube "blindly" or by feel. Some devices have been proposed in the past to assist in "blind" insertion of an endotracheal tube. For example, in U.S. Patent No. 4,612,927 to Kruger, an instrument is disclosed having open channel portions terminating in a head having a central cavity for engagement with the posterior end of the larynx. A tube can then be passed along the channel and directed into the trachea via a suitable ramp adjacent to the head of the instrument. U.S. Patent Nos. 4,054,135, 4,068,658, 4,067,331, and 4,069,820 to Berman all disclose a pharyngeal airway for intubation having a distal tip that engages the epiglottis to direct a tube into the trachea.

Summary of the invention

The aim of the present invention is to provide an improved guide for endotracheal intubation, which allows medical personnel after appropriate training to relatively easily insert a tube into the trachea.

According to the present invention there is provided a tracheal intubation guide for assisting in the insertion of a tube into the trachea of a patient, comprising:

a tubular member having a curved front end for insertion into the mouth and throat of a patient and for conforming to the curvature of the rear end of the tongue, a rear end extending out of the patient's mouth and having a passageway for receiving an endotracheal tube;

a bottom wall of the tubular part which extends along at least a portion of the length of the tubular part towards the front end; and

an elongated guide member extending from the underside wall to guide the tubular member over the tongue and into the patient's throat to a position above the laryngeal opening, the elongated guide member having a curvature adapted to the curvature of the front end of the tubular member;

characterized in that

the extended guide part has a front edge with a concave shape for engaging with the front side of the epiglottis and for grasping the hyo-epiglottic ligament.

Because the surface of the guide overlaps the hyo-epiglottic ligament, the tubular part is positioned opposite the laryngeal opening. When the guide passes through the a patient's mouth until the front edge of the guide surface is properly seated, an endotracheal tube previously inserted through the tubular member to its front end can be advanced into the trachea.

Accurate positioning of the guide can be determined by external palpation of the patient's neck. The epiglottis is a shield-shaped cartilage that rises above the tracheal opening or larynx. The epiglottis, located in front of the hyoid bone, is held in its midline by the hyo-epiglottic ligament. The hyoid bone is the highest palpable bone at the front of the neck and has a U-shaped structure that surrounds and suspends the larynx (the upper end of the trachea). The epiglottis is always located on the anterior higher part of the larynx and the guide of the invention uses this relationship for accurate positioning of the endotracheal tube.

Once accurate positioning is established, the hyo-epiglottic ligament is tensioned by a preliminary lift of the tongue and the epiglottis is raised from the front, opening the larynx immediately following the epiglottis. The tubular part of the guide is then positioned so that its open anterior end is directly opposite the laryngeal opening. The endotracheal tube can then be advanced through the anterior end of the guide into the larynx and trachea. The guide can now be removed, leaving the endotracheal tube in place.

The guide member may be formed integrally with the tubular member or may be a generally flat, J-shaped member secured to the front surface of the tubular member. The front edge of the guide surface preferably projects forwardly from the open front end of the tubular member. In a first embodiment of the invention, a pair of rollers are mounted on the front edge of the guide surface and the concave shape is defined by the opposing surfaces of the rollers which are intended to encompass the hyo-epiglottic ligament when the guide is properly positioned. The rollers facilitate sliding of the guide over the posterior end of a patient's tongue, which may be sticky in some patients. Additional rollers may be provided along the curved portion of the guide surface to facilitate sliding movement of the tracheal intubation guide. In a second embodiment of the invention, the surface of the guide is smooth and continuous with the concave shape at the front edge of the guide surface being defined by a pair of curved projections intended to encompass the hyo-epiglottic ligament. In the second embodiment, the guide similarly slides over the posterior end of the patient's tongue.

The tubular member itself preferably has portions with open areas to facilitate removal of the guide after the endotracheal tube has been inserted. The open areas are preferably provided with a continuous serpentine cutout extending the length of the tubular member and are designed so that an endotracheal tube is retained in the tubular member during positioning, but the guide can be easily removed after the tube has been advanced into the trachea. The rear end of the guide may have a suitable handle for an operator to hold during insertion of the guide and a toothed thumb rest to ensure alignment of the tubular member with the operator's hand, which assists in accurate positioning of the guide during insertion.

The invention also relates to a tracheal tracheal intubation device comprising a tracheal tracheal intubation guide, an endotracheal tube removably contained in the tubular part; and a tube in said endotracheal tube for supplying a local anesthetic from the rear end and for releasing the local anesthetic at the front end.

The tracheal intubation guide and device of the present invention facilitate proper intubation of the trachea, increasing the reliability and safety of the procedure. Since it does not require movement of the head or visualization of the larynx, it is particularly useful in the case of trauma or other emergency victims where the use of a laryngoscope may not be possible.

Short description of the drawing

The present invention will be better understood from the following description of a preferred embodiment of the invention in conjunction with the drawings, in which like reference numerals refer to like parts and in which:

Fig. 1 is a perspective view of a tracheal intubation guide according to the first embodiment of the invention;

Fig. 2 is a side view of the guide according to the first embodiment with an inserted endotracheal tube, showing how the guide is held.

Fig. 3 a known method for introducing an endotracheal hose with the head tilted backwards.

Figure 4 illustrates the insertion of an endotracheal tube according to the principles of the invention;

Figure 5 is a cut-away view of the mouth and throat area showing the insertion of the guide of the first embodiment;

Fig. 6 is a similar view with the end of the guide of the first embodiment seated over the hyo-epiglottic ligament and the endotracheal tube inserted through the guide of the first embodiment into the trachea;

Fig. 7 is a perspective view of a tracheal intubation guide according to a second embodiment of the invention;

Fig. 8 is a partial view showing the cross section of the front guide surface of the second embodiment;

Fig. 9 is an end view of Fig. 7 rotated 90° to illustrate the alignment of the front end with the front guide surface;

Figure 10 is a schematic representation of the orientation of the beveled tip of an endotracheal tube without an offset between the centerlines of the front end and the front guide surface;

Fig. 11 is a schematic representation of the orientation of the beveled tip when the centerlines are offset;

and

Fig. 12 is an illustration of a thin tube inserted into the endotracheal tube to introduce a local anesthetic during intubation.

Description of a preferred embodiment

Figures 1 and 2 of the drawings show a tracheal intubation guide according to a first embodiment of the present invention. The guide 10 consists essentially of a tubular member or guide tube 12 having a curved front end 14 and a generally straight rear end 16, a bottom surface 17 and a front guide surface 18 extending along at least a portion of the length of the bottom of the tubular member and beyond the front end of the tubular member. The guide surface 18 may be integral with the tubular member or suitably connected to the front surface of the member 12 and is suitably a generally flattened J-shaped strip as can be seen in Figures 1 and 2. In one example, the strip was approximately 3/4 inch (1.9 cm) wide, although other dimensions may be appropriate for patients of different ages.

As can be seen from Fig. 1, the front edge 20 of the guide surface 18 has a generally concave shape which in the first embodiment is defined by a pair of rollers or wheels 22, 24, the rollers or wheels suitably having inclined, opposing surfaces defining a concave shape or depression 26. The rollers 22, 24 preferably have a rounded, ball-like shape as shown in Fig. 1. A further pair of rollers 28, 30 is provided along the curved part of the guide surface 18.

The tubular member 12 has open areas along its length and in the first embodiment of the invention the member 12 has a serpentine slot or cutout 32 extending along its length. A suitable handle member is provided at the rear end of the member 12 by which the guide can be held by an operator as illustrated in Figure 2. The handle member has a suitable serrated thumb rest 36 having a rising surface 38 at its outer end for the operator's thumb 40 to rest on while holding the guide as shown in Figure 2. This ensures that the guide 10 is aligned with the operator's hand during insertion. The guide 10 is held by the operator in a manner similar to a conventional laryngoscope, with the operator standing by the patient's head.

The guide is rigid and can be made of any suitable non-toxic material, such as plastic. The curvature of the front end of the guide is designed to follow the general curvature of the back of the tongue and the front surface of the throat, as explained below.

The manner in which an endotracheal tube is introduced using the tracheal intubation guide in accordance with the features of the invention is best understood by referring to Figures 5 and 6 of the drawings which show a portion of a section through the head 42 of a patient. As shown in Figures 5 and 6, the tongue 44 curves downwardly at the back of the neck where the root of the tongue is anchored to the hyoid bone 46. The hyoid bone is a U-shaped structure which is arranged horizontally and opens backwards and which surrounds and supports the larynx 48. The larynx 48 forms the upper end of the windpipe or trachea 50. At the back of the windpipe is the esophagus 52 through which food and drink pass to the stomach. The epiglottis 54 is a shield-shaped cartilage which is located above the glottis 56 or the opening to the trachea and which protects the larynx. When food and drink is passed over the tongue towards the trachea, it is diverted laterally around the glottis and thus prevented from entering the larynx, which is also protected by the reflex of the vocal cords closing. The epiglottis 54 is anchored in front of the hyoid bone by the hyo-epiglottic ligament 59. The depression 58, which is limited at the front by the tongue, at the back by the epiglottis and at the bottom by the hyo-epiglottic ligament, is called the vallecula. In a frontal view, the depression 58 has a convex outline between the epiglottis and the hyoid bone above the hyo-epiglottic ligament. A preliminary pull on the base of the tongue moves the hyoid bone forward, which tightens the hyo-epiglottic ligament and thereby lifts the epiglottis forward and away from the glottis to expose the opening of the larynx.

Before describing the technique of inserting an endotracheal tube according to the present invention, reference is first made to Fig. 3 which illustrates a technique known in the art using a laryngoscope 62 to directly observe the insertion of the tube. The laryngoscope 62 must first be inserted as shown in Fig. 3, requiring that the patient's head be tilted backwards. In view of the risk of additional spinal cord injury as a result of such head movement, this technique is not usually used on injury victims. The tip of the laryngoscope spine 64 elevates the epiglottis.

The guide according to the invention allows a relatively precise, "blind" insertion of an endotracheal tube without the need to tilt or move the patient's head. As is illustrated by the use of the first embodiment of the guide shown in Figs. 1 and 2, an endotracheal tube is 70 with a cuff 71 attached to its front end is first moved from the rear to the front end of the tubular member 12 to the position shown in Fig. 4. With the head in the position shown in Fig. 4, the mouth is opened and the front end of the guide is inserted through the mouth as indicated by the arrow in Fig. 5. The guide surface slides over the tongue surface into the throat assisted by the rollers which ensure relatively smooth movement even when the tongue surface is sticky. The guide is inserted into the throat by the operator holding the handle member as shown in Fig. 2 until the front edge of the guide surface is engaged with the face of the epiglottis as shown in Fig. 6. As can be seen from Fig. 6, the curvature of the guide tube and front guide surface is designed to follow the curvature of the back of the tongue into the throat.

When the guide is centrally positioned, the concave depression on the anterior edge of the guide will sit or fit over the convex contour of the Hyo-Epiglottic Ligament as shown in Fig. 6, with one of the rollers on each side of the ligament. Proper positioning can be determined by external palpation of the sides of the neck in the region of the hyoid bone. If the guide does not sit precisely on the ligament, a lateral edge of the guide will be felt on one side of the neck above the hyoid bone. In this case, the guide is partially withdrawn and then reinserted. If the guide is properly seated, moving the guide laterally will result in general movement of the hyoid bone, which can be determined by external palpation of the neck.

Once an accurate positioning of the guide has been determined, the hyo-epiglottic ligament is tensioned by a previous lifting of the tongue and the epiglottis is lifted from the front, as shown in Fig. 6, opening the larynx immediately behind the epiglottis. The guide is designed so that the open front end of the guide tube and the end of the previously inserted endotracheal tube are positioned exactly opposite the opening of the trachea after lifting the epiglottis, as shown in Fig. 6.

The epiglottis can be lifted by lifting the tongue. However, in another embodiment, the guide may itself comprise a ramp (not shown in the figures of the drawing) for lifting the epiglottis, although this is not necessary for proper functioning of the guide. The ramp may conveniently comprise a 2.54 cm (1 inch) part hinged to the rear end of the guide surface approximately 2.54 cm (1 inch) from its front end and designed to hang down at a 45º angle during insertion of the guide. The ramp is connected to a lever of the handle part. When the guide has been placed in the correct position, the lever can be used to lift the ramp from the front and press the epiglottis between the ramp and the rear end of the guide surface. This would indicate that the epiglottis has been located and would also ensure maximum opening of the larynx.

Once accurate positioning of the guide has been ensured and the epiglottis has been raised, the endotracheal tube 70 is advanced through the tubular member 12 as shown in Fig. 6, which guides it down through the larynx and into the trachea. After the tube 70 has been fully inserted, the cuff 71 is inflated to hold the tube in place and the guide can be removed leaving the tube in place. The open area, the serpentine groove in the tubular guide member, holds the tube in the member 12 during positioning, but allows the guide 10 to be easily removed without changing the position of the tube 70 after it has been inserted, as indicated by the dotted lines in Fig. 6. When the tube 70 is in the position shown by the dotted lines position, the guide 10 can be easily removed.

Although in the previously described method an endotracheal tube was positioned in the tubular part before insertion into the throat, it can alternatively be positioned after the guide 10 has been inserted due to the open serpentine cutout and depending on its shape and location. For example, the intubation guide may be provided with an opening in its rear surface at the front end opposite the nasopharynx to allow the entry of an endotracheal tube inserted through the nose into the guide part 12 so that the endotracheal tube can be finally guided into the trachea. However, the insertion technique will usually be via the mouth as indicated in Figures 4 to 6.

A second embodiment of the guide is illustrated in Figures 7 to 9. The second embodiment is primarily characterized in that the front guide surface has a smooth continuous surface which is not interrupted by the rollers of the first embodiment. Thus, as in the first embodiment, the guide surface is mounted on the underside of the passageway and extends beyond the curved front end 14 of the guide tube 12. The guide surface of the second embodiment is designated 80. As explained, the guide surface 80 extends beyond the front end 14 of the guide and has a front edge 81 of a generally concave shape 84 which lies between a pair of curved projections 85a and 85b. As best seen in Figure 9, the front guide surface has a center line 87 which bisects the concave depression 84 and the front edge 81. The front end 14 of the guide tube additionally has a centerline 89 which is laterally offset from the centerline 87. As is known, the distal tip of the endotracheal tube 70 is normally beveled, whereby the bevel, indicated by reference numeral 91, looking down on the tube from above in Figures 10 and 11. If the centerlines of the front end 14 and the front guide surface of any of the embodiments described above were collinear, the engagement of the hyo-epiglottic ligament would result in a straight line arrangement between the beveled end 92 and the intervocal cord opening 93 in the larynx, as shown in Figure 10. In Figure 10, the tip of the bevel 92 is offset from the center of the intervocal cord opening 93, which may result in the beveled tip striking a vocal cord, preventing its entry into the trachea. In contrast, the offset between the centerlines, as shown in Figure 11, aligns the distal end of the tube 70 with the centerline of the front end 14. However, the bevel tip 92 is now substantially aligned with the centerline of the guide surface and therefore with the centerline of the vocal cord opening 93 in the larynx. This alignment increases the likelihood that the bevel tip 92 will pass through the vocal cords and into the trachea, thereby guiding the distal end of the endotracheal tube 70 through the vocal cords and trachea.

The guiding and insertion technique described above makes it possible for an endotracheal tube to be inserted "blindly" relatively easily and reliably. The technique does not require potentially injurious movement of a patient's neck or direct observation of the larynx, which may be obscured by blood, vomit or other foreign material that may be present in the pharyngeal cavity of victims of injury or those in cardiac arrest. Thus, a tube can be inserted relatively quickly and reliably into the trachea to clear a patient's airway and ensure adequate air supply.

A thin catheter 100 as shown in Fig. 12 may be provided extending from the rear to the front end of the guide and having a nozzle 102 at its front end 103. A slidable stop 104 retains the proximal end of the catheter 100 at the rear end of the tube 12. This arrangement may be used in conjunction with a local anesthetic syringe 105 attached to the rear end 106 of the catheter 100. The catheter 100 is inserted into the tube 70 and the guide with the inserted tube 70 is pushed into the throat of a patient. As the anesthetic in the catheter is released, it atomizes from the nozzles ahead of the guide to anaesthetize the tongue and larynx with a local anesthetic. This may assist in inserting the guide and endotracheal tube in awake patients.

Although a preferred embodiment of the invention has been described above by way of example, those skilled in the art will recognize that modifications to the disclosed embodiment are possible without departing from the scope of the invention, which is defined by the appended claims.

Claims (14)

1. A tracheal intubation guide to assist in inserting a tube into the trachea of a patient with: a tubular member (12) having a curved front end (14) for insertion into the mouth and throat of a patient and for conforming to the curvature of the posterior end of the tongue, a rear end (16) extending from the patient's mouth and having a through-bore (32) for receiving an endotracheal tube (70); a bottom wall (17) of the tubular part (12) extending along at least a portion of the length of the tubular part (12) toward the front end (14); and an elongated guide member (18, 80) extending from the lower wall (17) to guide the tubular member over the tongue and into the patient's throat to a position above the laryngeal opening, the elongated guide member (18, 80) having a curvature adapted to the curvature of the front end (14) of the tubular member (12); characterized in that: the extended guide part (18, 80) has a front edge (26, 81) with a concave shape for engaging with the front side of the epiglottis and for grasping the hyo-epiglottic ligament. 2. A guide according to claim 1, wherein the guide member (18, 80) is a flat generally J-shaped strip . 3. A guide according to claim 1, wherein the foremost edge of the guide member (18) has a pair of rollers (22, 24) attached thereto having opposing surfaces defining said concave shape (26), the pair of rollers (22, 24) having means for sliding the guide member (18) over the tongue and for engaging the hyo-epiglottic ligament. 4. A guide according to claim 1, wherein the guide member (80) is continuous and the concave shape (84) is a concave depression formed between a pair of curved projections (85a, 85b) at said foremost edge. 5. A guide according to claim 1, wherein the guide member (18) has a plurality of rollers (22, 24, 28, 30) that guide the guide member (18) over a tongue surface as the guide is inserted through the mouth and throat of a patient. 6. A guide according to claim 1, wherein the tubular member has open regions (32) extending along its length. 7. A guide according to claim 6, wherein the open areas (32) have a serpentine cutout (32) extending along the tubular part (12). 8. A guide according to claim 1, wherein the guide member (18, 80) extends forwardly from the front end of the tubular member (12). 9. A guide according to claim 1, wherein the tubular member (12) has a handle portion (34) at its rear end for gripping by an operator when inserting the guide into the patient's neck. 10. A guide according to claim 9, wherein the handle part (34) has a pronged thumb rest for aligning the tubular part (12) with the hand of an operator. 11. A guide according to claim 1, wherein the tubular member (12) has an opening in the rear surface of its front end facing the nasopharynx when the member is fully inserted for guiding an endotracheal tube inserted through the nose into the guide. 12. A guide according to claim 1, wherein the guide part has a centerline which substantially bisects said concave shape and wherein the tubular part (12) is arranged laterally offset from this centerline. 13. A guide according to claim 12, wherein the guide part is continuous and the concave shape is a concave depression (84) formed between a pair of curved projections (85a, 85b) at said foremost edge. 14. A tracheal intubation device comprising: a tracheal intubation guide according to claim 1; an endotracheal tube (70) removably contained in the tubular part (12); and a tube (100) in said endotracheal tube (70) for supplying a local anesthetic from the rear end (16) and for releasing the local anesthetic at the front end (14)